Damper apparatus for air conditioning system

ABSTRACT

The invention relates to a damper apparatus for an air conditioning system for more accurately adjusting air volume in accordance with opening ratio of a damper blade. The damper apparatus includes a plurality of damper blades and an actuator for rotating the damper blade. The apparatus also includes an air flow path dividing means for dividing an air flow path in a duct into upper and lower regions with respect to a rotation axis of the damper blade and exerting resistance to air flow between the biased damper blade and the air flow path dividing means. The invention effectively suppresses air overflow with the air flow path dividing means to decrease the air volume surpassing the opening ratio, thereby more accurately adjusting air volume.

CLAIM OF PRIORITY

This application claims the benefit of Korean Patent Application No.2006-24934 filed on Mar. 17, 2006, in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an air volume control apparatus(hereinafter, referred to as a damper apparatus) for automaticallycontrolling air volume supplied to and exhausted from a room inaccordance with temperature change therein. More particularly, theinvention relates to a damper apparatus for an air conditioning systemwhich exerts air resistance in accordance with open angle of the damperblade to air flow in a duct to effectively suppress air overflow due tothe biased damper blade, and which measures average air flow velocity bymeasuring average differential pressure or dynamic pressure at manylocations within the duct to accurately calculate air volume, therebymore accurately adjusting air volume in accordance with opening ratio ofthe damper blade.

2. Description of the Related Art

In general, an air conditioning system as a part of an automatic controlsystem for a building includes a damper apparatus for adjusting volumeof air supplied to or exhausted from a room in order to maintainpleasant room temperature or conserve energy by optimally controllingthe room temperature.

FIG. 1 is an overall configuration view of such an air conditioningsystem.

As shown in FIG. 1, conventional damper apparatuses 200 are provided inthe air conditioning system, more particularly, installed in a supplyair duct 210 through which outside air is supplied, an exhaust air duct310 through which outgoing air is exhausted, and a return duct 410 forreturning the re-circulated air. Each of the damper apparatuses 200includes a plurality of damper blades 230 for adjusting air volumeflowing therethrough and an actuator 240 for rotating the damper blades230.

The conventional air conditioning system also includes a filter 332 forfiltering out foreign material in the supply air, and a heating unit 222for heating the supply air to a predetermined temperature, a coolingunit 223 for cooling down the supply air to a predetermined temperatureand a humidifier 224 for providing moisture to the supply air.

In addition, a supply air fan 232 is disposed inside the supply air duct210, and an exhaust air fan 234 is disposed inside the exhaust air duct310.

As shown in FIG. 2, in the conventional damper apparatus 200 for an airconditioning system, when outside air is introduced to the airintroduction duct 210, a differential pressure sensor 250 sensespressures from the front and back sides of the damper blade 230 to inputthe differential pressure to a controller 260. The controller 260arithmetically calculates the differential pressure of the outside airsensed by the differential pressure sensor 250 and the cross-sectionalarea of the duct 210 to calculate the air volume inside of the duct 210.

In order to adjust the opening ratio of the damper blade 230, thecontroller 260 calculates the difference between the current roomtemperature and the desired room temperature and calculates the airvolume that needs to be supplied to the room considering the volume ofthe room. Then, the controller 260 calculates the opening ratio of thedamper blade 230 corresponding to the air volume to be supplied.

Then, the controller 260 operates the actuator 240 to control the damperblade 230 in accordance with the opening ratio calculated.

Therefore, in the conventional damper apparatus 200 for the airconditioning system, the actuator 240 rotates the damper blade 230 inaccordance with the calculated result of the controller 260, increasingor decreasing the opening ratio to adjust the temperature as desired bythe user. As such, the conventional damper apparatus 200 for the airconditioning system achieves air volume control through adjusting theopening ratio of the damper blade 230, and thus it is essential that theair volume should be accurately adjusted corresponding to the openingratio.

FIG. 3 is a graph showing the opening ratio and the air volume changeratio obtained by the above conventional damper apparatus 200 for theair conditioning system.

The most ideal characteristics of the damper apparatus 200 for the airconditioning system is to obtain an air volume change ratio line Bidentical with line A in direct proportion to the opening ratio. Whenthese lines are in agreement, it is most desirable because thecontroller 260 provided in the damper apparatus 200 for the airconditioning system is able to adjust the opening ratio as desired viathe actuator 240 and the damper blade 230, thereby providing accuratevolume of air corresponding to the opening ratio.

Examining the air volume change ratio line B as shown in FIG. 3, as thedamper blade 230 is rotated in an arbitrary angle θ to be at about 50%of the opening ratio, the resultant air volume change ratio is too largeat about 80% or more due to air overflow.

The reason for this is because, at an arbitrary opening ratio, thedamper blade 230 induces the air flow to move from an upper region(front side) to a lower region (back side) with respect to the rotationaxis 230 a. In this process, the biased damper blade 230 exertsacceleration to the air flow to result in air overflow in which greatervolume of air flows in the lower region of the damper blade 230.

Therefore, the air volume change ratio with respect to the opening ratiois expressed as a saturation curve of line B, greatly deviating fromline A which is in direct proportion to the opening ratio.

Therefore, the air volume change ratio curve B obtained by the damperapparatus 200 for the air conditioning system is completely differentfrom line A which is in direct proportion to the opening ratio,indicating as a result, that it is difficult for the user to adjust airvolume via adjusting the open angle of the damper blade. Therefore, theair overflow occurring with the conventional damper apparatus 200 forthe air conditioning system must be suppressed to accurately adjust airvolume in accordance with the opening ratio.

Therefore, there have been suggested several conventional technologiesto overcome such a problem.

An example of such conventional technologies is suggested in JapanesePatent Application Publication Hei 6-337162.

In this conventional technology, each of a plurality of blades aredesignated into each of a plurality of regions with each bladeindividually controlled in a different direction from one another,thereby obtaining an air volume change ratio for the entire damperapparatus, which approximates to the line in direct proportion to theopening ratio of the damper apparatus.

However, as the damper blades are divided into regions and controlledrespectively, a plurality of actuators are needed to rotate the damperblades in different directions, which in turn increases the totalmanufacture costs of the damper apparatus.

Moreover, such a conventional damper apparatus fails to obtain an airvolume change ratio that is approximate to the opening ratio to asatisfactory level.

Another conventional technology is suggested in U.S. Pat. No. 5,730,652,entitled “Damper With Stationary Pitot-Static Sensing Vanes.”

This conventional damper apparatus has sensors installed between thedamper blades for sensing the air volume flowing through the damperblades. The opening ratio of the damper blade is adjusted using thedynamic pressure measured via these sensors.

Such a conventional structure is practical such that dynamic pressurecan be accurately measured to adjust air volume.

However, the problem with this conventional technology is that as thedamper apparatus is used over time, measurement errors occur due to thestructure of the sensors. That is, due to back flow of the air passingthrough the damper blade, the static pressure measuring portion isclogged by foreign material.

Thus, precision and operational reliability of the conventional damperapparatus is degraded over time.

In addition, the conventional apparatus yields too small an open area ata low opening ratio, impossible to adjust the air volume, which leavesroom for improvement.

Further, in this conventional structure, the number of sensors forsensing air volume via measuring dynamic pressure is less than that ofthe damper blades. That is, three sensors are disposed in comparison tofour damper blades. This is because the sensors are disposed between thedamper blades, and thus the number of sensors is smaller than the numberof damper blades by 1.

Therefore, the conventional technology has room for improvement in termsof a need for measuring the average dynamic pressure at greater numberof locations in a duct to more accurately measure the air volume.

SUMMARY OF THE INVENTION

The present invention has been made to solve the foregoing problems ofthe prior art and therefore an object of certain embodiments of thepresent invention is to provide a damper apparatus for an airconditioning system capable of effectively suppressing air overflow dueto a biased damper blade, with simple structural improvements, therebyaccurately adjusting air volume.

Another object of certain embodiments of the invention to provide adamper apparatus for an air conditioning system which measures averagedifferential pressure, i.e., dynamic pressure at more various andgreater number of locations in a duct to accurately measure air volume,thereby accurately adjusting air volume.

According to an aspect of the invention for realizing the object, thereis provided a damper apparatus for an air conditioning system foradjusting air volume in a duct, including: a plurality of damper bladeseach disposed rotatably to open and close an air flow path; an actuatorfor rotating the damper blades; and an air flow path dividing meansdisposed at an air inlet side for dividing the air flow path inside theduct into an upper region and a lower region with respect to a rotationaxis of the damper blades and exerting resistance to air flow betweenthe damper blade biased toward the air inlet side and the air flow pathdividing means.

According to another aspect of the invention for realizing the object,there is provided a damper apparatus for an air conditioning system foradjusting air volume in a duct including: a plurality of damper bladeseach disposed rotatably to open and close an air flow path; an actuatorfor rotating the damper blades; and an air flow path dividing meansdisposed at an air inlet side for dividing the air flow path inside theduct into an upper region and a lower region with respect to a rotationaxis of the damper blades and exerting resistance to air flow betweenthe damper blade biased toward the air inlet side and the air flow pathdividing means; and an average pressure measuring unit having an averagetotal pressure measuring part and a static pressure measuring part formeasuring an average differential pressure or dynamic pressure of airflowing in the duct.

Preferably, the air flow path dividing means comprises a separationplate disposed at a front side of the damper blade.

Preferably, the separation plate has sealing material at an end portionand side end portions thereof, the sealing material providing sealingwith the rotation axis of the damper blade and with the duct.

Preferably, the average pressure measuring unit is provided in a numberthat corresponds to the number of damper blades.

Preferably, the average total pressure measuring part comprises aplurality of total pressure measuring holes formed toward the air inletside, on a front side of the air flow path dividing means, each of thetotal pressure measuring holes comprising an air induction portionhaving a sloped inner surface.

Preferably, the average static pressure measuring part comprises aplurality of static pressure measuring holes formed on an underside ofthe air flow path dividing means.

Preferably, the rotation axis of the damper blades and the air flow pathdividing means are shifted upward or downward from a center of thedamper blades.

Preferably, an upper part of the damper blades is opened forward and alower part thereof is opened backward in a position where the rotationaxis of the damper blade and the air flow path dividing means areshifted downward from the center of the damper blade.

Preferably, an upper part of the damper blades is opened backward and alower part thereof is opened forward in a position where the rotationaxis of the damper blade and the air flow path dividing means areshifted upward from the center of the damper blade.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a configuration view of an air conditioning system accordingto prior art;

FIG. 2 is a configuration view of a damper apparatus for the airconditioning system according to prior art;

FIG. 3 is a graph showing the air volume change ratio obtained by theconventional damper apparatus for the air conditioning system incomparison to a line in direct proportion to the opening ratio;

FIG. 4 is a perspective view illustrating the exterior of a damperapparatus for an air conditioning system according to the presentinvention;

FIG. 5 is a sectional view illustrating the damper apparatus for the airconditioning system according to the present invention;

FIG. 6 is an enlarged sectional view illustrating in detail the damperapparatus for the air conditioning system according to the presentinvention;

FIG. 7 is a partially cut and enlarged perspective view illustrating anair flow path dividing means and an average pressure measuring unit inthe damper apparatus for the air conditioning system according to thepresent invention;

FIG. 8 is a sectional view illustrating a variation of the damperapparatus for the air conditioning system according to the presentinvention, in which a rotation axis of a damper blade and the air flowpath dividing means are shifted from a center of the damper blade; and

FIG. 9 is a graph showing the air volume change ratio line with respectto the opening ratio, obtained by the damper apparatus for the airconditioning system according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Preferred embodiments of the present invention will now be described indetail with reference to the accompanying drawings.

As shown in FIGS. 4 and 5, a damper apparatus 1 for an air conditioningsystem according to the present invention includes a plurality of damperblades 20 rotated inside a duct for opening and closing an air flow pathand an actuator for rotating the damper blades 20.

In addition, the damper apparatus 1 includes an air flow path dividingmeans 40 for dividing the air flow path inside the duct 10 at an airinlet side into an upper region and a lower region with respect to arotation axis 20 a of the damper blade 20 and for exerting resistance toair flow between the damper blade 20 biased toward the air inlet sideand the air flow path dividing means 40.

In addition, the air flow path dividing means 40 preferably is disposedat a front side of each of the damper blades 20 in alignment with therotation axis 20 a of the damper blades 20. The air flow path dividingmeans 40 comprises a separation plate 42 (see FIG. 7) for dichotomizingair flow passing through the damper blade 20 into upper and lower flows,and can be installed inside the duct 10 using additional installationpiece (not shown).

The separation plate 42 has sealing material (not shown) at an endportion and side portions thereof, i.e., at a portion of the rotationaxis 20 a and side surface portions of the duct 10. The sealing material(not shown) provides sealing between the separation plate 42 and therotation axis of the damper blade 20 and between the separation plate 42and side surface portions of the duct 10.

In addition, as shown in FIGS. 6 and 7, each of the air flow pathdividing means 40 includes an average pressure measuring unit 50 havingan average total pressure measuring part 52 and an average staticpressure measuring part 54 to measure average differential pressure,i.e., dynamic pressure in the air flow inside the duct 10.

The average pressure measuring unit 50 is provided in a numbercorresponding to the number of damper blades 20. As shown in FIGS. 6 and7, the average total pressure measuring part 52 of the average pressuremeasuring unit 50 comprises a plurality of total pressure measuringholes 52 b formed on the front side of the air flow path dividing means40, i.e., at the air inlet side. Each of the total pressure measuringholes 52 b comprises an air induction portion 52 a having a sloped innersurface to facilitate inflow of air for measuring the average totalpressure.

On the other hand, each of the average static pressure measuring parts54 comprises a plurality of static pressure measuring holes 54 a in anunderside of the air flow path dividing means 40 and downstream of theair flow from the total pressure measuring holes 52 b. Such aconfiguration minimizes chances of foreign material in the air cloggingthe static pressure measuring holes 54 a and the effect of turbulence toallow accurate measurement of the static pressure.

As shown in FIG. 7, the average total pressure measuring part 54 and theaverage static pressure measuring part 54, constituting the averagepressure measuring unit 50, each has a structure having one sideobstructed by a plug 56 a, 56 b and the other side connected to a sensor(not shown) of the average pressure measuring unit 50.

According to a certain embodiment of the present invention, the rotationaxis 20 a of the damper blade 20 and the air flow path dividing means 40are shifted (offset) upward or downward from a center of each of thedamper blades 20. As shown in FIG. 8, the rotation axis 20 a of thedamper blade 20 and the air flow path dividing means 40 can be shifteddownward.

In these structures, a closed space S3 enclosed by the damper blade 20and the air flow path dividing means 40 is formed larger, resulting in alarger area of resistance to the air flow, and thereby air overflow ismore effectively prevented.

As shown in FIG. 5, the damper apparatus 1 for the air conditioningsystem with above described configuration adjusts air volume within arange from vertical position of the damper blade 20 completely blockingthe air flow path where the open angle θ is 0° to horizontal position ofthe damper blade 20 completely opening the air flow path where the openangle θ is 90°.

In this process, in the damper apparatus 1 according to the presentinvention as shown in FIG. 6, when the plurality of damper blades 20 aresimultaneously opened in an arbitrary angle θ by the actuator 30, eachof the damper blades 20 is provided with the air flow coming from theair inlet side, divided by the air flow path dividing means 40 into theair flow in the upper region S1 and the air flow in the lower region S2.

In the upper region S1 where the upper air flow is provided, an upperpart of each of the damper blades 20 is biased forward. Therefore, ineach of the closed spaces S3 enclosed by the air flow path dividingmeans 40 and the damper blade 20, air flow is blocked from moving fromthe upper part of the damper blade 20 to the lower part thereof, causinggreat resistance. Thus, the air flow moving into the enclosed space S3finely changes its direction upward to flow through an open region S1-1.

In this process, according to a certain embodiment of the presentinvention, the air flow moving from the upper region S1 to the lowerregion S2 of each of the damper blades 20 is blocked due to the closedspace S3.

On the other hand, as the damper blade 20 is biased backward in thelower region S2 of the air flow path dividing means 40, the airintroduced into the lower region of the air flow path dividing means 40flows well along the biased surface of the damper blade 20 through anopen region S2-1. There is no air flow moving in from the upper regionS1 by the air overflow.

As described above, according to the present invention, in the damperapparatus 1 for the air conditioning system, the closed space S3enclosed by each of the damper blade 20 and air flow path dividing means40 blocks the air flow moving from the upper region S1 to the lowerregion S2, causing great resistance to the air flow in the upper regionS1. Therefore, air overflow in which the air flow moves over the biaseddamper blade 30 with the conventional damper apparatus is effectivelysuppressed.

In addition, according to a certain embodiment of the present invention,each of the average pressure measuring units 50 provided in each of theair flow path dividing means 40 measures average values of totalpressures and static pressures at each location. Then, the averagepressure measuring unit 50 transmits the differential pressure, i.e.,dynamic pressure as an electric signal to the controller (not shown) bya differential pressure measuring device, and the controller calculatesthe air volume based on this signal.

In this process, the average total pressure measuring part 52 of theaverage pressure measuring unit 50 is disposed on the front side of theair flow path dividing means 40, i.e., the air inlet side. In addition,the average total pressure measuring part 52 comprises a plurality ofair induction portions 52 a having a sloped inner surface to facilitateinflow of air, corresponding to the number of total pressure measuringholes 52 b. The average static pressure measuring part 54 of the averagepressure measuring unit 50 comprises a plurality of static pressuremeasuring holes 54 a formed in an underside of the air flow pathdividing means 40, downstream of the air flow from the total pressuremeasuring holes 52 b. Therefore, chances of foreign material in the airgetting inside and also the effects of turbulence are minimized toaccurately measure the static pressure.

Particularly, air inflow to the average pressure measuring unit 50 isfacilitated even at low air flow velocity and thus even subtledifferential pressure can easily be measured. Also, the static pressuremeasuring holes 54 a are located in the downstream of the air flow fromthe total pressure measuring holes 52 b and on the underside of the airflow path dividing means 40, and thus minimally affected by turbulence.

Further, the average pressure measuring unit 50 according to a certainembodiment of the present invention is formed integral with the air flowpath dividing means 40 installed for each of the damper blades 20. Thisallows measuring the differential pressure, i.e., dynamic pressure atvarious locations and at greater number of locations, thereby allowingmore accurate air volume measurement and accurate adjustment of airvolume.

In addition, according to a certain embodiment of the present invention,in the damper apparatus 1′ for the air conditioning system, the rotationaxis 20 a of the damper blade 20 and the air flow path dividing means 40are shifted (offset) in a predetermined distance L from a center of thedamper blade 20.

Such a shifted structure is illustrated in FIG. 8. In the damperapparatus 1′ for the air conditioning system shown in FIG. 8, therotation axis 20 a of the damper blade 20 and the air flow path dividingmeans 40 are shifted downward from the center K of the damper blade 20in a predetermined distance L. This shift is effective in a structure inwhich the upper part of the damper blade 20 is opened forward and thelower part thereof is opened backward.

Shifting the rotation axis 20 a of the damper blade 20 and the air flowpath dividing means 40 downward from the center K of the damper blade 20further enlarges the closed space S3 enclosed by the damper blade 20 andthe air flow path dividing means 40, increasing resistance to the airflow in the upper region of the damper blade 20. Thereby, the airoverflow caused by the air flowing from the upper region to the lowerregion over the damper blade 20 is more effectively suppressed.

Although FIG. 8 illustrates the structure in which the rotation axis 20a of the damper blade 20 and the air flow path dividing means 40 areshifted in a predetermined distance L from the center K of the damperblade 20, the present invention is not limited by such. Alternatively,the rotation axis 20 a of the damper blade 20 and the air flow pathdividing means 40 can be shifted upward from the center K of the damperblade 20.

In this case, air overflow can be effectively suppressed even in astructure in which the upper part of the damper blade 20 is openedbackward and the lower part thereof is opened forward.

Therefore, according to certain embodiments of the present invention,the shift distance L of the rotation axis 20 a of the damper blade 20and the air flow path dividing means 40 can be adjusted from the centerK of the damper blade 20 to adjust resistance to the air flowing throughthe damper blade 20, thereby more effectively controlling air overflowdue to the biased damper blade 20.

FIG. 9 is a graph showing the air volume change ratio with respect tothe opening ratio obtained by certain embodiments of the presentinvention.

The damper apparatus 1 for the air conditioning system according to thepresent invention allows an air volume change ratio line B′approximating greatly to line A in direct proportion to the openingratio. Therefore, the controller provided in the damper apparatus 1 forthe air conditioning system according to the present invention canadjust the opening ratio as desired via the actuator 30 and the damperblade 20, thereby providing exact corresponding air volume to a room.

According to the air volume change ratio line B′, even if the openingratio of the damper blade 20 is at 50%, the corresponding air volumechange ratio is considerably reduced from 80% obtained by theconventional apparatus, thereby greatly improving air overflow occurringwith the conventional apparatus.

The reason for this is because the air flow path dividing means 40 isinstalled at the front side of the rotation axis 20 a of the damperblade 20 to divide the air flow path inside the duct 10 into upper andlower regions with respect to the rotation axis 20 a of each of thedamper blades 20, exerting resistance to the air flow between the damperblade 20 biased toward the air inlet side and the air flow path dividingmeans 40, thereby effectively suppressing air overflow.

As a result, according to certain embodiments of the present invention,the damper apparatus 1 for the air conditioning system yields the airvolume change ratio expressed as curve B′ with respect to the openingratio in FIG. 9. Curve B′ approximates more greatly to line A in directproportion to the opening ratio than the conventional air volume changeratio curve B.

Therefore, with the damper apparatus 1 for the air conditioning systemaccording to the present invention, by adjusting the opening ratio, theuser is able to accurately adjust air volume approximating to theopening ratio.

According to certain embodiments of the invention as set forth above, anair flow path dividing means can effectively suppress air overflowpassing through the damper blade to decrease the excessive air volumewith respect to the opening ratio, thereby allowing more accurateadjustment of air volume.

Furthermore, according to certain embodiments of the invention, averagedifferential pressure, i.e., dynamic pressure can be measured at morevarious and greater number of locations in a duct to enable accuratemeasurement of air volume, thereby allowing accurate adjustment of airvolume.

Certain exemplary embodiments of the invention have been explained andshown in the drawings as presently preferred. This invention may,however, be embodied in many different forms and should not be construedas limited to the embodiments set forth herein. While the presentinvention has been shown and described in connection with the preferredembodiments, it will be apparent to those skilled in the art thatmodifications and variations can be made without departing from thespirit and scope of the invention as defined by the appended claims.

1. A damper apparatus for an air conditioning system for adjusting airvolume in a duct, comprising: a plurality of damper blades each disposedrotatably to open and close an air flow path; an actuator for rotatingthe damper blades; and a plurality of air flow path dividing meansdisposed at an air inlet side for dividing the air flow path inside theduct into an upper region and a lower region with respect to a rotationaxis of the damper blades and exerting resistance to air flow betweenthe damper blade biased toward the air inlet side and the air flow pathdividing means.
 2. The damper apparatus for an air conditioning systemaccording to claim 1, wherein the air flow path dividing means comprisesa separation plate disposed at a front side of the damper blade.
 3. Thedamper apparatus for an air conditioning system according to claim 2,wherein the separation plate has sealing material at an end portion andside end portions thereof, the sealing material providing sealing withthe rotation axis of the damper blade and with the duct.
 4. The damperapparatus for an air conditioning system according to claim 1, whereinthe rotation axis of the damper blades and the air flow path dividingmeans are shifted upward or downward from a center of the damper blades.5. The damper apparatus for an air conditioning system according toclaim 4, wherein an upper part of the damper blades is opened forwardand a lower part thereof is opened backward in a position where therotation axis of the damper blade and the air flow path dividing meansare shifted downward from the center of the damper blade.
 6. The damperapparatus for an air conditioning system according to claim 4, wherein,an upper part of the damper blades is opened backward and a lower partthereof is opened forward in a position where the rotation axis of thedamper blade and the air flow path dividing means are shifted upwardfrom the center of the damper blade.
 7. A damper apparatus for an airconditioning system for adjusting air volume in a duct comprising: aplurality of damper blades each disposed rotatably to open and close anair flow path; an actuator for rotating the damper blades; and aplurality of air flow path dividing means disposed at an air inlet sidefor dividing the air flow path inside the duct into an upper region anda lower region with respect to a rotation axis of the damper blades andexerting resistance to air flow between the damper blade biased towardthe air inlet side and the air flow path dividing means; and a pluralityof average pressure measuring units and each average pressure measuringunit having an average total pressure measuring part and a staticpressure measuring part for measuring an average differential pressureor dynamic pressure of air flowing in the duct.
 8. The damper apparatusfor an air conditioning system according to claim 7, wherein the airflow path dividing means comprises a separation plate disposed at afront side of the damper blade.
 9. The damper apparatus for an airconditioning system according to claim 8, wherein the separation platehas sealing material at an end portion and side end portions thereof,the sealing material providing sealing with the rotation axis of thedamper blade and with the duct.
 10. The damper apparatus for an airconditioning system according to claim 7, wherein the average pressuremeasuring unit is provided in a number that corresponds to the number ofdamper blades.
 11. The damper apparatus for an air conditioning systemaccording to claim 7, wherein the average total pressure measuring partcomprises a plurality of total pressure measuring holes formed towardthe air inlet side, on a front side of the air flow path dividing means,each of the total pressure measuring holes comprising an air inductionportion having a sloped inner surface.
 12. The damper apparatus for anair conditioning system according to claim 7, wherein the average staticpressure measuring part comprises a plurality of static pressuremeasuring holes formed on an underside of the air flow path dividingmeans.
 13. The damper apparatus for an air conditioning system accordingto claim 7, wherein the rotation axis of the damper blades and the airflow path dividing means are shifted upward or downward from a center ofthe damper blades.
 14. The damper apparatus for an air conditioningsystem according to claim 13, wherein an upper part of the damper bladesis opened forward and a lower part thereof is opened backward in aposition where the rotation axis of the damper blade and the air flowpath dividing means are shifted downward from the center of the damperblade.
 15. The damper apparatus for an air conditioning system accordingto claim 13, wherein, an upper part of the damper blades is openedbackward and a lower part thereof is opened forward in a position wherethe rotation axis of the damper blade and the air flow path dividingmeans are shifted upward from the center of the damper blade.